The Curse of Oak Island follows brothers Marty and Rick Lagina, originally from Kingsford, Michigan, through their efforts to find the speculated treasure or historical artifacts believed to be on Oak Island. The series discusses the history of the island, recent discoveries, theories, and prior attempts to investigate the site.[4] Areas of interest include the "Money Pit", Borehole 10-x, Smith's Cove, "Nolan's Cross", the "Hatch" and the "Swamp".

The Lagina brothers became fascinated with the island after reading the January 1965 issue of Reader's Digest magazine that features an article on the Restall family's work to investigate the so-called "Money Pit".[5] Marty and his brother Rick obtained a controlling interest in Oak Island Tours, which reportedly owns most of the island. The brothers were later approached by Prometheus Entertainment to do a reality show. Rick and Marty have engaged the assistance of father-and-son Dan and Dave Blankenship, permanent residents of the island who have likewise been searching for treasure since the 1960s.[6]

The series explores various Oak Island theories through conversations with independent researchers. Persons featured have included Zena Halpern discussing her theory about North African gold and sharing copies of a French map of the island which she claims is dated 1347; J. Hutton Pulitzer discussing his theory of ancient mariner visitations; Petter Amundsen discussing his theory about codes hidden in Shakespearen literature and a secret project involving Sir Francis Bacon and the Rosicrucians; Daniel Ronnstam discussing his theory about the 90 foot stone being a dual cypher containing instructions as how to defeat the money pit flood tunnels with corn; authors Kathleen McGowen and Alen Butler discussing their theory involving the fabled Knights Templar treasure and an alleged relocation of historical religious artifacts to the island; and John O'Brien discussing his theory that the island contains treasures of the Aztec Empire.

Having started in 2014, The Curse of Oak Island has run for four seasons. On August 2, 2016, it was announced that Nova Scotia Business Inc. approved $1,271,546 in film funding for the production of the most recent 4th season.[8] When asked about a 5th season, creator Kevin Burns said that it all depends on the Lagina brothers. Burns said that the brothers are "not reality show people", and have always been "reluctant" to do more seasons as filming keeps the brothers away from their families for up to five months. Burns also released a statement saying: "We are not set to come back for another year, take of that what you will", leaving the future of the show uncertain.[9]

Brothers Rick and Marty Lagina now own most of Oak Island. Determined to resurrect the 200-year-old search for treasure, they explore an abandoned shaft called Borehole 10-X and use water pressure to pump material to the surface. They find a tiny piece of metal.

A scuba team that includes Marty's son Alex Lagina dives Smith's Cove and finds what are claimed to be non-indigenous coconut fibres and anomalous stones. Meanwhile, more metal fragments and cat bones are found in the slurry from 10-X.

A visitor to the island presents Rick and Marty Lagina with his theory about where the treasure on Oak Island is located and the idea that the Menorah might be among the treasures for which they are searching.

The team drills in the area of the money pit but is unable to drill through the underground material. A visitor shows them alleged evidence that the treasures from King Solomon's Temple could be buried on Oak Island.

After hearing that a treasure of biblical proportions was buried on Oak Island 2500 years ago, Rick and Marty Lagina unsuccessfully look for evidence to prove it while also trying to locate the original Money Pit.

A visitor comes to the island suggesting that he has discovered a secret method of getting to the treasure. He claims that Francis Bacon has left behind instructions to the effect that the "flood tunnels" can be disabled by pouring corn into the money pit. The team declines to test the theory and instead visits a masonic lodge. The team searches the swamp again and finds nothing.

While work begins in the swamp, Rick and Marty travel to Scotland to investigate more corn-related theories about the money pit. They are also presented with a theory that Oak Island is a copy of King Solomon's Temple and that the entrance to the Money Pit is in the swamp.

Difficulties are encountered during the dive to the bottom of borehole 10X, the team further investigates Fred Nolan's property and an alleged Roman sword found in the waters off Oak Island is presented to the team.[44]

The team agrees to turn focus over to the Money Pit and review what they have collected. A researcher presents a copy of what she claims is a French map from 1347 of Oak Island. The map shows locations for a "hatch", a "valve" and an "anchor" on the Island which raises discussion about an object from Africa.[51]

While preparing to excavate the Money Pit, the team investigates an 18th century well on mainland Nova Scotia. The team brings in an archaeologist to inspect a hole on Dave Blankenship's property which they think is a potential "hatch".

The swamp is drained and searched with a metal detector revealing an old spike. Object not dated. C-1 Dig Site is drilled to target depth of 170 ft. where previously inserted camera may have seen something shiny and gold colored.

A camera sent down 10X confirms the divers impression that there is nothing there of note, undermining the camera's operators previous assertion that they were 90% certain there was a chest there. Some of the team are in denial about this and insist there is still some point in exploring 10-X further on the basis that Dan Blankenship has spent so much time on it, it must be the key to the alleged puzzle.

The new examination of borehole 10X concludes. Equipment failure delays excavation of a new hole. Rick heads to the Franklin D. Roosevelt library to learn why the late President was interested in Oak Island.

The team attempts to decode a cipher and concludes that they only possess 1/7th of the cipher. Rocks are found at Smith's Cove. The investigation of the cove is halted for the year. A man from Arizona claims, without any evidence, that several hundred tons of gold are hidden in tunnels near Oak Island.

The final excavation of the season leads to the discovery of scrap metal pieces, a washer, several hex nuts and a button. Season finale featured McGinnis gold cross, Barrotte spike of Spanish galleon ship, and other artifacts evaluated by Dr. Lori Verderame